The present invention relates to electric load management and, more particularly, to a load management system and method.
In an effort to obtain control over electric power demand, attention has become focused on room air conditioner units and other appliances that are heavy power users. For example, within one typical metropolitan area it was estimated that there were 2.7 million residential air conditioning units in use during the summer of 1986. Assuming that the average unit size is 9500 BTU, demand is approximately 1.05 KW. If control could be exercised over operation of just 10 percent of the total units in operation so as to shut down those units on command, demand could be reduced by approximately 270,000 units.times.1.05 KW=283.5 MW.
Because of the portability of room air conditioners, the fact that they are located on the premises of customers and can be plugged into almost any branch circuit, control of operation by the power utility is not a simple matter. In an endeavor to solve the problem a scheme was developed, as will be described herein, that relies on the cooperation of the customer.
To carry out the scheme a device was required that could be turned over to a customer for connection between the customer's air conditioner unit and the power outlet, which device could be programmed or controlled by the utility to shut down operation of the conditioner during certain times. Additionally, a financial incentive was believed to be necessary to induce life style and comfort level changes. The device had to be reliable and, if it was to be part of an incentive program, it had to be tamper proof.
As the program was conceived, the customer would be furnished with a device having at least a modular component part which, after a specified period of time, would be returned to the utility. If it could be confirmed that the customer installed the device and did not interfere with or alter its operation, the customer would be given appropriate financial compensation. Of course, it will be apparent that the basic concept is not limited to room air conditioner units but is applicable to other appliances and the like. For convenience, however, the invention will be described first with reference to room air conditioners.